The importance of photosynthesis is unlimited. A short description is given regarding this:

Manufacture of plant food: To live food is essential. Green plants manufacture food by the process of photosynthesis. If the green plant would not be able to manufacture food, then no plant could live in this world.

Supply of food for Animal Kingdom: Only green plants manufactures food by the process of photosynthesis. No animal, even man can manufacture their food. Rice, Bread, Fruits Fish Meat, Milk etc. whichever we eat all we get directly or indirectly from plants. So the Animal Kingdom is completely dependent on green plants, and the green plant manufacture these food by the process photosynthesis. So it can be said, the process of photosynthesis prepares of all the foods for both plants and animals.

Source of Energy: Much energy is exhausted in our works and movements. Source of this energy is food. Green plants manufacture food by the process of photosynthesis. Energy comes to food from the Sun light energy trapped as chemical energy in foods manufacture by photosynthesis. Food breaks down in every living cell producing energy. Source of our all energy is food and source of energy of food is the sun. So Sun is the source of all energy. Energy that needs in metabolic activities in plants and animals come from food too.

Ecological Balance: In maintaining Ecological Balance particularly balancing the ratio of O2 and CO2, photosynthesis plays a special role. The amount of oxygen gas in the airs 20.946% and that of carbon dioxide is 0.033%. This is the normal amount of oxygen and carbon dioxide gas in the atmosphere. For normal growth and living of plants and animals in this world, amount of these gases should be within normal range. On variation of the normal ratio the atmosphere will be imbalanced. We know respiration goes on in every living being (plants and animals).

In respiration O2 gas is taken in and CO2 gas is driven out. Plants and animals both are taking O2 and releasing CO2 during respiration. If this system goes on successively there would have shortage of O2 and excess of CO2. But as green plants absorb CO2 and release O2 during Photosynthesis, so the ratio of O2 and CO2 in the atmosphere is still all right. Due to excessive deforestation the ratio of these two gases in the atmosphere is being destroyed. Therefore, we should have to plant trees more and more.

Contribution of Photosynthesis in Human Civilization: Men survive only because photosynthesis is present in green plants. But apart from the survival, the contribution of photosynthesis is unlimited in the arena of human civilisation. Coal, Petrol, Rayon, Cellophane, Paper, Rubber and Medicines etc. all are the gift of plant’s.